1. Field of the Invention
The invention relates to a pneumatic tube system in which a carrier is moved rapidly by air pressure or vacuum through conveyor tubes extending between terminals. More particularly, the invention relates to a pneumatic tube system used to carry out banking operations in which a carrier which passes through conveyor tubes is removable from the system at either of the two terminals which may comprise a customer terminal and a teller terminal connected by two conveyor tubes.
2. Description of the Prior Art
Pneumatic tube banking systems in present day use are of two general types, i.e., (1) a captive carrier system and (2) a non-captive or removable carrier system.
Typical captive carrier systems or components are shown, for example, in U.S. Pat. Nos. 3,232,559, 3,237,881, 3,237,882, and 3,237,884. Such captive carrier systems usually involve carrier travel back and forth through a single tube between the customer and teller terminals.
Typical non-captive carrier systems or components are shown, for example, in U.S. Pat. Nos. 3,787,008, 3,788,577, 3,828,698, and 3,867,593. Non-captive carrier systems have used either a single tube extending between the customer and teller terminals through which the carrier travels in either direction; or have used two tubes, a send tube and a receive tube, connected to and extending from the remote customer terminal to the teller terminal.
U.S. Pat. No. 3,867,593 shows a carrier detector used in a single tube non-captive carrier system which may be used to detect and signal direction of carrier movement. Such a system involves changing the direction of air pressure or vacuum in the single tube, depending on the desired direction of a carrier movement. This arrangement also entails sealing the ends of the conveyor tube at each terminal for effective control of the movement of air through the conveyor tube for sending or delivering a carrier from or to a particular terminal at one or the other end of the conveyor tube.
Pneumatic single-tube systems used for banking services, whether of captive or non-captive carrier type, involve many problems relating, among others, to complex arrangement of components to provide delivery and dispatch means of a carrier at either the customer or teller terminal, special holding and release devices at the arrival and send chambers or compartments at each terminal, special blower controls and air direction reversal, timers, etc.
Non-captive carrier systems also have been used involving two conveyor tubes extending between the terminals, one for sending and one for receiving a carrier from or at a terminal. Many of the problems associated with single tube non-captive carrier systems also characterize prior two-tube non-captive carrier systems. In addition, normally the arrangement of two-tube systems involves other difficulties in conveniently locating at each terminal the carrier arriving or being dispatched, assuming that the tubes as normally installed follow a side by side or up and down relative location as connected between the two terminals of the system.
Furthermore, prior non-captive carrier systems have terminals which include spring-controlled doors that have increasing resistance while being opened, either to insert a carrier or by carrier movement on arrival, which may require additional manual effort or may increase wear on or damage to a carrier from repeated carrier-door collision. Also, where timers are used for blower operation, the time interval must be sufficient to permit heavily loaded carriers to traverse the distance between terminals. This, of course, increases the blower on-time for movement of an unloaded carrier between terminals beyond that required, which results in decreased efficiency of power use.
Also, prior terminal structures have combined the terminal cabinet or enclosure members and the framework on which components are mounted within the cabinet. Difficulties result in servicing, repairing, adjusting, or replacing components of any terminal because of relative inaccessibility of components within such cabinet.
These described deficiencies of or objectionable features in prior pneumatic tube systems have resulted in systems very expensive to install or operate or use, systems which are noisy in operation, systems that are unreliable in operation, and systems that have complex arrangement and structure of components. These problems, as stated, for the most part exist with respect to two-tube non-captive systems as well as the other types of pneumatic tube banking systems described.
Thus, there exists a need in pneumatic tube banking systems for simple, reliable, inexpensive, quietly operating non-captive carrier system structures and arrangements of customer and teller terminals and connected two-tube conveyor tube components, in which the terminal structures and multiple tube connections between such terminals have improved and simplified structures combined and coordinated with a simplified blower and blower control system.